These structures are useful for manufacturing flexible or rigid packagings, such as packets or bottles for foodstuffs. These packagings can be manufactured by coextrusion, laminating or coextrusion blow-moulding.
The prior art EP 35392 describes coextrusion binders consisting of:
(i) 1 to 100 weight % of an ethylenic resin modified by grafting originating from an ethylenic polymer which contains 0 to 15 mol % of at least one alpha-olefin having 3 to 30 carbon atoms, as comonomer, and which has an MI.sub.2 /[.eta.].sup.-8.77 ratio which, in absolute value, is not less than 15 and a relative density of 0.88 to 0.98 g/cm.sup.3, and PA0 (ii) 99 to 0 weight % of a non-modified ethylenic polymer containing 0 to 50 mol % of at least one alpha-olefin having 3 to 30 carbon atoms, as comonomer, and which has an MI.sub.2 /[.eta.].sup.-8.77 ratio which, in absolute value, is not less than 15 and a relative density of 0.86 to 0.96 g/cm.sup.3, PA0 (a) an ethylene content of at least 80 mol % PA0 (b) a carboxylic acid content (or content of its derivative) of between 0.01 and 10 weight % of the binder PA0 (c) a relative density of 0.88 to 0.98 g/cm.sup.3 and PA0 (d) an MI.sub.10 /MI.sub.2 ratio of 5 to 18.
and which have